Saved from a watery crash by the aircraft's shadow

I was doing Part 2 of a Takeoff Runway Requirements Test which requires me to be able to bring the aircraft to a standstill within the confines of the runway if I aborted the takeoff at V1. I selected KPFN runway 32 as it is 6,315 feet long at an elevation of 19 feet and my estimated minimum needed was 6,280 feet at MSL. When I began the takeoff roll I was unaware of the (19 foot ?) drop at the end of the runway.

As the pictures show, I failed the test which ended in spectacular fashion, the aircraft weight (static nosewheel pavement load 17,301 lb) seemingly supported by nothing more than the aircraft's shadow.

Second attempt was more successful, nosewheel on the grass at the end of the runway, no damage to the boundary fence.

In that situation, if you decide to abort halfway down the runway, brake hard, and swerve slightly to th right of left. By making a turn at the and you will add a few extra yards to the distance available.

Also, if they weren't yet fully extended, extend flaps, and spoilers. (from the pics it looks like you did that.) And push the nose down. Push the stick forward all the way.

You could also (at reasonable speed,) start a snaking motion. turn right, and when reaching the edge of the runway, swerve left, etcetera. It adds some distance. Plus it will slow you down.

Be carefull thoug, keep it under controll. keeping the nose pushed down helps keep control when swerving.

Yes the sick-bags will come out, but the ambulances can stay in...

enjoy!

Thanks for the input, much appreciated.

Prompted by your response I ran the tests again to see how much of the 6,315 ft runway I was using to get to V1 by pausing the takeoff at exactly V1 and taking overhead screenshot to work out the distances using Paint.

Used 61.0% using B727-100 with JT8D-9's in ISA conditions, zero wind (6,295 ft runway required at MSL for TOW 160,540 lb, V1 124 Kias with flaps 25°). Managed to stop with the nosewheel on the runway 14 numbers short of the runway threshold.

Used (as pictured) 62.6% using B727-100 with JT8D-15's in ISA conditions, zero wind (6,295 ft runway required at MSL for TOW 170,000 lb, V1 127 Kias with flaps 25°). Managed to stop with the nosewheel on the runway threshold.

Used 65.5% using B727-200 with JT8D-15's in ISA conditions, zero wind (6,295 ft runway required at MSL for TOW 170,000 lb, V1 127 Kias with flaps 25°). Still managed to stop with both mains and nosewheel on the runway threshold.

Used 63.3% using B727-100 with JT8D-17's in ISA + 25°F conditions, zero wind (6,280 ft runway required at MSL for TOW 170,000 lb, V1 127 Kias with flaps 25°). Still managed to stop (second attempt) with the nosewheel on the grass beyond the runway threshold.

Should I be getting a B727 to V1 in much less than 60+% of the minimum required runway length ?

Haven't had any problems with Part 1 of the Takeoff Runway Requirements Test (takeoff within the minimum required runway length).

dunno really, I never fly that plane. plus I usually use longer runways. and I don't do much stopping either ;)

But I'll hazzard a guess...

I think the Minimum required lenght you have is a specification of that particular aircraft. (it will be different for other aircraft.

And I think the Minimum length has probably been calculated (or measured) at Minimum weight. So maybe with only 10% or 20% fuel, just enough to fly a short distance.

Try that.

At a lower weight you accellerate much faster, so you will be at speed sooner. (50%, 40% RW)

And stopping will be easyer too!

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If you still find it hard to stop, maybe the numbers you have there for minimum RW length are estimated a bit low.

In that case, make a note of the real RW length required.

I don't know if you should reach v1 at 40% 50% or 60% of the runway. Depends on how good your brakes are too I suppose (!!)

Speaking of brakes.check: options-settings-controls - keyboard assignments.

Check the "Brakes"-key assignment, and make sure the slider is set all the way to the right (for maximum braking).

The minimum runway lengths I'm using were compiled from published B727 takeoff runway length requirements charts and I'm using them in these tests to test the takeoff performance of the various JT8D engines I'm using.

I have checked the brake slider as suggested (thanks) and increased the spoiler drag to equal flap drag.

It would appear from the results of these tests that the engine parameters I'm using need a little more work.